Egg treatment process and product



Patented Nov. 17, 1936 EGG TREATMENT PROCESS AND PRODUCT Faw Yap Chuck,San Francisco, Calif.

No Drawing. Application February 3, 1936, Serial No. 62,046

19 Claims. (Cl. 99170) This invention relates generally to processes forthe treatment of eggs to effect their preservation, and to products ofmanufacture resulting from such processes. Certain features of theinvention disclosed herein may be deemed an improvement of the inventiondisclosed and claimed in my copending application Serial Number 730,071,filed June 11, 1934,

In my aforesaid co-pending application I have disclosed an eg treatmentprocess making use of a coating material containing a dissolved alkalineearth compound capable of ready conversion by carbon'dioiiide to form asubstantially insoluble alkaline earth carbonate. The material in thatinstance is in the form of an emulsion of a water solution and mineraloil, a suitable alkaline earth compound being calcium hydroxide. Forconverting the calcium hydroxide or like como pound to calciumcarbonate, I rely in that instance upon carbon dioxide from thesurrounding atmosphere and carbon dioxide evolved from the interior ofthe egg.

It is an object of the present invention to provide a superior processfor egg treatment, and a superior product resulting from the process.stead of relying upon carbon dioxide from the atmosphere, or carbondioxide evolved from'the interior of the egg, to convert the dissolvedcalcium compound to calcium carbonate, I now provide a positive chemicaltreatment for this purpose, which rapidly carbonates the calciumcompound. Thus no extended period of time is required to provide acoating of the desired character. I also provide ingredients in thecoating material tending to promote 'better preservation of the eggs,and ingredients serving to form a buiier salt system in the finalcoating. Likewise an ingredient or ingredients are provided which serveto increase the carbon dioxide tension on the 40 surface of the egg,whereby the-contents of the egg are more effectively preserved. Thecoating produced by the present invention is also superior.

with respect to its physical characteristics, in that it is more firmlybonded to the surface of the egg shell, and afiords a more attractiveappearance. I

Further objects of the invention will appear from the followingdescription in which the preferred embodiments of .the invention havebeen set forth in detail.

The process consists generally in first applying a primary liquidcoating material to the exterior surface of the egg, which contains adissolved alkaline earth compound capable of ready conversion to formthe desired alkaline earth carbonate. Immediately following applicationof this coating material, a secondary liquid is applied, which containsan HCO3 radical, to combine with the alkaline earth compound to form asub stantially insoluble alkaline earth carbonate, and

to leave an excess of the bicarbonate.

In its simplest form, the primary coating material may consist of asaturated solution of calcium lactate in water, emulsified with aneutral mineral oil, like white oil. The secondary treatment liquid canconsist of a water solution of sodium or potassium bicarbonate, likewiseemulsified with mineral oil by the use of an emulsifying agent like acalcium soap. Assuming that the surface of an egg has first been coatedby use of the primary coating material, application of the secondarysolution causes a reaction between the calcium lactate remaining uponthe surface of the 1 eg and the H003 radical of the bicarbonatesolution, to form substantially insoluble calcium carbonate, and sodiumor potassium lactate. The first coating material need not, be anemulsion, but may merely consist of a saturated solution of calciumlactate, with reliance upon the mineral oil of the secondary liquid, tosupply an oil film. Likewise if the primary coating material is anemulsion, the second coating material may be a simple water solution.

A third possible modification is to employ a simple water solution ofcalcium lactate for the first application, and a simple solution ofsodium or potassium bicarbonate for the secondary treatment. In a thirdoperation, a supplemental treatment liquid is applied. The supplementalliquid in such event should contain a binder, like casein,

which will enhance the desired chalky appearance and surface texture,and which will also serve as a preservative. For example thesupplemental liquid can consist of 5% by weight of casein dissolved inone part of commercial sodium It is desirable to employ the sodium orpotassium carbonate in the secondary solution, in concentrationssufliclent to afiord an excess of unconverted carbonate'in the finalcoating. The eifect of such a coating in the preservation of the egg, issimilar to maintaining an egg in an atmosphere of carbon dioxide gas.Metabolism of the egg content is accompanied by evolution of carbondioxide gas through the pores of the shell. Placing an egg in a chambercontaining carbon dioxide retards the rate of metabolism, byincreasingthe carbon dioxide tension about the egg whereby'evolution of carbondioxide is minimized. Bicarbonate on the egg shell makes possible acomparable eiIect, in increasing the tension of carbon dioxide.

While the above procedures will give good results, I prefer to utilizemore complicated soluand preferably a substance like sodium silicatetions which have been found to be more effective. Thus in place of asimple saturated solution of a calcium compound in water, I utilize aless alkaline solution containing several calcium salts, as for exampleone containing calcium lactate, calcium chloride and a calcium acetate.As an example of suitable proportions, grams of 'cal-.

cium lactate, 22 grams of calcium chloride and 10 grams of calciumacetate, can be employed for each 100 cc. of water. Assuming that thisprimary treatment liquid is to be emulsified with mineral oil, about 2grams of gum arabic or /3 gram of tragacanth can be added, and about 400cc. of this solution emulsified with about 600 cc. of mineral oil, usingabout gramof a calcium soap like calcium stearate, as emulsifying agent.A sufficient amount of a mild organic acid, such as lactic acid, isadded to this material to adjust its hydrogen ion concentration to about6.5, that is, slightly acid to phenol-phthalein indicatorr In place ofcalcium acetate, a similar amount of calciumgluconate can'be employed.

A preferred secondary treatment liquid, to be applied to the eggfollowing the-application of the coating. material described above, canconsist of sodium bicarbonate, potassium bicarbonate, sodium benzoateand sodium phosphate, dissolved in water. As an example of suitableproportions, 16 grams of sodium bicarbonate, 20 grams of potassiumbicarbonate, 2 grams of sod- ,ium benzoate, and 9 grams of sodiumphosphate,

can be employed for each 100 cc. of water. This carbonating solution canlikewise be emulsified with a mineral oil, by the aid of a calcium soap,suitable proportions being about 600 cc. of the solution with about 400cc. of mineral oil.

Use of the several calcium salts, including calcium lactate, calciumchloride, and calcium acetate, for the primary coating material, makesit possible to provide a relatively large content of dissolved calciumin the applied coating, As-

-suming that an egg is first coated by use of the preferred primarytreatment liquid specified, com

taining calcium lactate, and other calcium salts, the subsequentapplication of the preferred secondary liquid specified, causes areaction to occur between the calcium salts and the bicarbonate salts,in which a major part of the calcium lac-- tate is converted to calciumcarbonate, with simultaneous formation of-sodium and potassium lactate.Likewise calcium carbonate is formed by conversion of the calciumchloride and calcium acetate or gluconate salts, with simultaneousformation of sodium and potassium chlorides tion is not altered to anymaterial degree, but

its presence on thesurface of the egg supplements other salts present,particularly the sodium and potassium lactates and bicarbonates, toprovide a buffer salt system. This buffer salt system is desirable inthat when moisture from the atmosphere-is deposited upon the surface ofth e as during cold storage, a buffer salt solution is formed having apH value of about 7.5 to 8. This pH value of the final coating can beadjusted to fall within the limits desired by varying the amount oflactic acid introduced into the primary treatmentliquid. The albumen.content of the eg'gnormally has a hydrogen ion concentration of from 7.9to 8, but metabolism tends to shift the pH valueto the alkaline sidewith evolution of CO2. I have found that the presence of such a buffersalt mixture on the surface of the egg shell, together with an increasedcarbon dioxide tension, definitely tendsto minimize a shift in the pHvalue of the contents of the egg, and therefore retards the metabolismrate, or a change in thick egg white to thin and weakening of the yolkmembrane. The benzoate of soda, specified for the carbonating solution,is desirable in that it tends to prevent mold formation.

As previously explained in connection with the simplified treatmentliquids first specified,- mineral oil can likewise be omitted from themore complex treatment liquids. In such event the supplemental treatmentliquid is employed, consisting for example of 5% of casein by weightdissolved in one part of commercial sodium silicate solution, togetherwith four parts of water. The casein content of such a third treatmentmaterial is precipitated to serve as a binder, and serves as asubstitute for a thin film of mineral oil, while the sodium silicatecontent enhances the chalky appearance of the treated 'egg, and providesa desirable surface texture.

With respect to the mechanical procedure followed in applying thematerials specified, it is desirable to apply the primary coatingmaterial in such a manner asto secure good penetration into the pores ofthe egg shell, whereby in the final coating the pores of the shell willbe effectively plugged. One procedure which has been found beneficial inthis respect, is to first heat the eggs by subjecting them to radiantheat, after which they are sprayed with the primary treateggs, so thatwhen the eggs are cooled the liquid tends to be sucked into the pores ofthe shell. As an alternative, or as an adjunct to such treatment, highpressure spraying means can be employed, so that theparticles of liquidmaterial are *impacted upon the surfaces of the eggs at high plied.After applying theprimary coating material, excess liquid is removedfrom the surface of the egg by an air blast, after which the eggs areimmediately sprayed with the carbonating liquid. Following treatment bythe carbonating liquid, excess liquid is again removed by an air blast,and if the supplemental treatment liquid is being employed, this canlikewise be sprayed upon the eggs, to be followed by blowing off ofexcess liquid and drying.

Eggs treated according to the preferred procedures outlined above havedesirable keeping qualities both at ordinary atmospheric temperatures,and in cold storage. Loss of weight, over a period of time, issubstantially the same as eggs which have been processed byconventionalmethods, utilizing dipping of eggs in hot mineral oil.However, for eggs stored aigiven period of time, thecondition of thewhites and yolks, is markedlysuperior in quality to eggs processed byconshell, and to the buffer salt mixture and bicarbonate provided, whichdefinitely retard metabolism and decomposition of the albumen content.The coating is relatively tenacious and firmly bonded to the shell, andbecause of the chalky appearance and texture afforded, enhances theappearance of the eggs. Whereas conventional processing methodsemploying mineral oil, can be applied only to eggs which have not beensand blasted, my process can be applied equally well to all classes ofeggs, whether sand blasted or not.

I claim:

1. In a process for the preservation of eggs, applying a liquid coatingmaterial to the surface of the egg, the material containing a dissolvedalkaline earth compound capable of ready conversion to form asubstantially insoluble alkaline earth carbonate, and then applying acarbonating solution to the'exterior of the egg.

2. In a process for the preservation of eggs, applying a liquid coatingmaterial to the surface of the egg, the material containing calciumlactate dissolved in water, and then applying a carbonating solution tothe egg.

3. In a process for the preservation of eggs, applying a liquid coatingmaterial to the surface of the egg, the material containing an alkalineearth compound capable of ready conversion to form a substantiallyinsoluble alkaline earth carbonate, and then applying to the exterior ofthe egg awater solution containing a dissolved alkali metal bicarbonate.

4. Ina process for the preservation of eggs, applying a liquid coatingmaterial to the surface of the egg, the material including calciumlactate dissolved in water, and then applying to the exterior of the egga water solutioncontaining alkali metal bicarbonate.

5. In a process for 'the preservation of eggs, applying a liquid coatingmaterial to the surface of the egg, the material containing calciumlactate dissolved in water, together with additional dissolved calciumsalts capable of ready conversion to form calcium carbonate and thenapply containing a dissolved alkali metal bicarbonate.

. 6. In a processv for the preservation of eggs,

applying a liquid coating material to the surface of the egg,thematerlal including a calcium lactate dissolved in water, secondlyapplying to the exterior of the egg a carbonating solution and thenapplying to the surface of the eggv a water solution containing sodiumsilicate and casein.

'7;- In a process for the preservation of eggs,

subjecting thesurface of the egg to liquid spray material, said materialcontaining a calcium compound dissolved in water and capable of readyconversion to form calcium carbonate, removing excess liquid from theegg by subject'mg the same,

to a blast of air and then spraying the egg with bicarbonate ion.

9. As a new article of manufacture, an egg having a supplementalvdeposit of alkaline earth carbonate integrally bonded to its naturalshell and serving to reduce the natural porosity of the shell, togetherwith a lactate.

of affording a 10. As a new article of manufacture, an egg having asupplemental deposit of alkaline earth carbonate integrally bonded toits natural shell and serving to reduce the natural porosity of theshell, together with an alkali metallactate an an alkali metalphosphate.

11. As a new article of manufacture, an egg having a supplementaldeposit of calcium carbonate integrally bonded to its shell and servingto reduce the natural porosity of the shell, together with an alkalimetalv lactate, and alkali metal phosphate, and an alkali metalbicarbonate.

12. As a new article of manufacture, an egg having a supplementaldeposit containing calcium carbonate and calcium silicate integrallybonded to.its shell and serving to reduce the natural porosity of theshell.

13. As a new article of manufacture, an egg having a supplementaldeposit of calcium carbonate integrally bonded to its shell and servingto reduce the natural porosity of the shell, together with an alkalimetal lactate, an alkali metal phosphate, sodium silicate andprecipitated casein as a binder. I

14. As a new article of manufacture, an egg having a supplementaldeposit of calcium car bonate integrally bonded to its shell and servingto reduce the natural porosity of the shell, to-.

- gether with an alkali metal bicarbonate and other salts capable ofaffording a pH value of from 7.5 to 8 when moistened.

15. In a process for the preservation of eggs, applying a liquid coatingmaterial tothe surface ofthe egg, the material consisting of oilemulsified with a water solution containing an alkaline earth compoundcapable of ready conversion to form a substantially insoluble alkalineearth carbonate, and then applying to the exterior of the egg a watersolution containing a dissolved .alkali metal bicarbonate.

16. In a process for the preservation of eggs, applying a liquid coatingmaterial to the surface of the egg, the material containing an alkalineearth compound capable of ready conversion to form a substantiallyinsoluble alkaline earth carbonate, and'then applying to the exterior ofthe egg a liquid material consisting of oil emulsified with a watersolution of an alkali metal bicarbonate.

17. In a process for the preservation of eggs,

applying a liquid coating material to the surface of the egg, thematerial consisting of oil emulsified with a water solution containingan alkaline earth compound capableof ready conversion to form asubstantially alkaline earth carbonate,

and then applying to theexterior of .the egg a liquid materialconsisting of oil emulsified with a water solution of an alkali metalbicarbonate.

18'. In a process for the preservation of eggs;..

applying a liquid coating material to the surface of the egg, thematerial containing calcium lactate dissolved in water and having a pHvalue of about 6.5, and then applying to the surface of the egg a watersolution containing an alkali metal bicarbonate.

19. In a process for the preservation of eggs, applying a slightlyacidliquid coating material to the surface of the egg, said-materialincluding a dissolved alkaline earth compound capable of readyconversion toform substantially insoluble alkaline earth carbonate, andthen applying to the exterior of the egg a water solution containing asoluble alkali metal bicarbonate, together with sodium phosphate.

FAW YAP CHUCK.

